The high accuracy of ribosomal protein synthesis was believed to rely on the fidelity of two key biosynthetic steps, but a research team has found that a previously unknown step is a third important contributor to the fidelity of the process (Nature2009, 457, 161). The two known steps on which mistake-free protein synthesis depends are the enzymatic addition of correct amino acids to each of the amino acid-specific transfer RNAs and the ribosome's selection . . .